Tuesday, October 7, 2014

Conclusions

National fatality data indicate that the three
most common forklift-related fatalities involve forklift overturns,
workers on foot being struck by forklifts, and workers falling from
forklifts. The case studies indicate that the forklift, the factory
environment, and actions of the operator can all contribute to fatal
incidents involving forklifts. In addition, these fatalities indicate
that many workers and employers are not using or may be unaware of
safety procedures and the proper use of forklifts to reduce the risk of
injury and death.

Recommendations

Employers

Reducing
the risk of forklift incidents requires a safe work environment, a safe
forklift, comprehensive worker training, safe work practices, and
systematic traffic management.
NIOSH recommends that employers and
workers comply with OSHA regulations and consensus standards, maintain
equipment, and take the following measures to prevent injury when
operating or working near forklifts.

Worker Training

Make sure that workers do not operate a forklift unless they have been trained and licensed.

Develop,
implement, and enforce a comprehensive written safety program that
includes worker training, operator licensure, and a timetable for
reviewing and revising the program. A comprehensive training program is
important for preventing injury and death. Operator training should
address factors that affect the stability of a forklift—such as the
weight and symmetry of the load, the speed at which the forklift is
traveling, operating surface, tire pressure, and driving behavior.

Inform
operators of sit-down type forklifts that they can be crushed by the
overhead guard or another part of the truck after jumping from the
overturning forklift. The operator of a sit-down type forklift should
stay with the truck if lateral or longitudinal tip over occurs. The
operator should hold on firmly and lean away from the point of impact.

Train
operators of stand-up type forklifts with rear-entry access to exit
from the truck by stepping backward if a lateral tip over occurs.

Ensure
that operator restraint systems are being used on sit-down type
forklifts. Since 1992, forklift manufacturers have been required to
equip new sit-down type forklifts with operator restraint systems. Many
manufacturers of these forklifts offer restraint systems that can be
retrofitted on older forklifts. Many of the fatalities resulting from
overturns of sit-down type forklifts might have been prevented if the
operator had been restrained. The overhead guard of the forklift is
generally the part that crushes the operator's head or torso after he or
she falls or jumps outside of the operator's compartment. The risk of
being crushed by the overhead guard or another rigid part of the
forklift is greatly reduced if the operator of a sit-down type forklift
remains inside the operator's compartment. Because many forklifts are
not equipped with a restraint system and operator compliance is less
than 100% on forklifts equipped with a restraint system, operators
of sit-down type forklifts should be instructed not to jump from the
operator's compartment but to stay inside by leaning in the opposite
direction of the overturn.

Train operators to handle asymmetrical loads when their work includes this activity.

Forklift Inspection and Maintenance

Establish a vehicle inspection and maintenance program.

Retrofit old sit-down type forklifts with an operator restraint system if possible.

Lifting

Ensure
that operators use only an approved lifting cage and adhere to general
safety practices for elevating personnel with a forklift. Also, secure
the platform to the lifting carriage or forks.

Provide means for
personnel on the platform to shut off power to the truck whenever the
truck is equipped with vertical only or vertical and horizontal controls
for lifting personnel.

Workers on Foot

Separate forklift traffic and other workers where possible.

Limit some aisles to workers on foot only or forklifts only.

Restrict
the use of forklifts near time clocks, break rooms, cafeterias, and
main exits, particularly when the flow of workers on foot is at a peak
(such as at the end of a shift or during breaks).

Install physical barriers where practical to ensure that workstations are isolated from aisles traveled by forklifts.

Evaluate
intersections and other blind corners to determine whether overhead
dome mirrors could improve the visibility of forklift operators or
workers on foot.

Make every effort to alert workers when a
forklift is nearby. Use horns, audible backup alarms, and flashing
lights to warn workers and other forklift operators in the area.
Flashing lights are especially important in areas where the ambient
noise level is high.

Work Environment

Ensure
that workplace safety inspections are routinely conducted by a person
who can identify hazards and conditions that are dangerous to workers.
Hazards include obstructions in the aisle, blind corners and
intersections, and forklifts that come too close to workers on foot. The
person who conducts the inspections should have the authority to
implement prompt corrective measures.

Install the workstations,
control panel, and equipment away from the aisle when possible. Do not
store bins, racks, or other materials at corners, intersections,or other
locations that obstruct the view of operators or workers at
workstations.

Enforce safe driving practices such as obeying
speed limits, stopping at stop signs, and slowing down and blowing the
horn at intersections.

Repair and maintain cracks, crumbling edges, and other defects on loading docks, aisles, and other operating surfaces.

Workers

Do not operate a forklift unless you have been trained and licensed.

Use seatbelts if they are available.

Report to your supervisor any damage or problems that occur with a forklift during your shift.

Do
not jump from an overturning, sit-down type forklift. Stay with the
truck if lateral or longitudinal tip over occurs. Hold on firmly and
lean in the opposite direction of the overturn.

Exit from a stand-up type forklift with rear-entry access by stepping backward if a lateral tip over occurs.

Use extreme caution on grades, ramps, or inclines. Normally you should travel only straight up and down.

On all grades, tilt the load back if applicable, and raise it only as far as needed to clear the road surface.

Do not raise or lower the forks while the forklift is moving.

Do not handle loads that are heavier than the rated weight capacity of the forklift.

Operate the forklift at a speed that will permit it to be stopped safely.

Slow down and sound the horn at intersections and other locations where vision is obstructed.

Look toward the path of travel and keep a clear view of it.

Do not allow passengers to ride on forklift trucks unless a seat is provided.

When dismounting from a forklift, always set the parking brake, lower the forks, and neutralize the controls.

Do not drive up to anyone standing in front of a bench or other fixed object.

Do not use a forklift to elevate workers who are standing on the forks.

Do not elevate a worker on a platform unless the vehicle is directly below the work area.

Whenever a truck is used to elevate personnel, secure the elevating platform to the lifting carriage or forks of the forklift.

Use
a restraining means such as rails, chains, or a body belt with a
lanyard or deceleration device for the person(s) on the platform.

Thursday, September 25, 2014

The cases presented here were investigated by the NIOSH Fatality
Assessment and Control Evaluation (FACE) Program. The case reports were
selected to represent the most common types of fatal forklift incidents:
(1) forklift overturns, (2) workers struck, crushed, or pinned by a
forklift, and (3) falls from a forklift.

Case 1-Forklift Overturn

On
September 18, 1996, the 43-year-old president of an advertising sign
company was killed while using a sit-down type forklift to unload steel
tubing from a flatbed trailer. He was driving the forklift about 5 miles
per hour beside the trailer on a concrete driveway with a 3% grade. The
victim turned the forklift behind the trailer, and the forklift began
to tip over on its side. The victim jumped from the operator's seat to
the driveway. When the forklift overturned, the victim's head and neck
became pinned to the concrete driveway under the falling-object
protective structure (overhead guard). An inspection of the forklift
revealed that the right-side rear axle stop was damaged before the
incident and was not restricting the lateral sway of the forklift when
it turned. Also, slack in the steering mechanism required the operator
to turn the steering wheel slightly more than half a revolution before
the wheels started to turn. The forklift was not equipped with a seat
belt [NIOSH 1996b].

Case 2-Forklift Overturn

On April 25,
1995, a 37-year-old shop foreman was fatally injured after the sit-down
type forklift he was operating overturned. The victim was turning while
backing down an incline with a 4% grade. The forklift was transporting a
3-foot-high, 150-pound stack of cardboard with the forks raised
approximately 60 inches off the ground. No one witnessed the incident.
The victim was found with his head pinned under the overhead guard. The
forklift was not equipped with a seat belt [California Department of
Health Services 1996].

Case 3-Forklift Overturn

On
November 25, 1996, a 41-year-old male laborer was fatally injured when
the sit-down type forklift he was operating fell off a loading dock and
pinned him under the overhead guard. The forklift was not equipped with a
seat belt. The loading dock had large cracks in the surface and was in
need of extensive repair. It was raining when the victim left the
storage building to lift a load from the back of a pickup truck.
Evidence indicates that either the victim's forklift was too close to
the outer edge of the loading dock (which crumbled) or the right front
tire was caught in a large crack in the loading dock, causing the
forklift to overturn [Indiana State Department of Health 1996].

Case 4-Worker Struck by Forklift

On
October 19, 1995, a 39-year-old female punch press operator at a
computer components manufacturer was fatally injured while performing
normal work tasks at her station. A forklift was traveling in reverse at
high speed toward the victim's work station. A witness observed the
forklift strike a metal scrap bin (about 3 by 5 by 3½ feet), propelling
it toward the punch press station. The bin hit the press and rebounded
toward the forklift. There it was hit once again and shoved back against
the corner of the press, striking and crushing the victim against the
press [NIOSH 1996c].

Case 5-Fall from Forklift

On July 21,
1997, a 36-year-old male electric-line technician was fatally injured
after falling from and being run over by a forklift. While the operator
was driving the forklift, the victim was riding on the forks. As the
operator approached an intersection, he slowed down and turned his head
to check for oncoming traffic. When he turned his head back, he could
not see the victim. He stopped the forklift, dismounted, and found the
victim underneath the right side of the forklift [NIOSH 1997a].

Case 6-Fall from Forklift

On
September 24, 1997, a 61-year-old male maintenance manager of a shelter
for the homeless died after falling 7 feet from a safety platform that
had been elevated by a forklift. The victim had been raised in a
steel-framed, cage-type safety platform that had not been secured to the
forklift. The victim removed a fluorescent light bulb from its fixture
and stepped to one side of the safety platform. When the victim shifted
his weight from the center of the platform to the outer edge, the safety
platform toppled off the forks. The victim fell about 7 feet, struck
his head on a concrete floor, and was subsequently struck by the steel
safety platform [NIOSH 1997b].

Case 7-Fall from Forklift

On
September 6, 1995, a 47-year-old male assistant warehouse manager was
fatally injured while working with a forklift operator to pull tires
from a storage rack. The two workers had placed a wooden pallet on the
forks of the forklift, and the victim then stood on the pallet. The
operator raised the forks and victim 16 feet above a concrete floor to
the top of the storage rack. The victim had placed a few tires on the
pallet when the operator noticed that the pallet was becoming unstable.
The victim lost his balance and fell, striking his head on the floor
[NIOSH 1996a].

Tuesday, September 16, 2014

Background

Forklifts, also known as powered industrial
trucks, are used in numerous work settings, primarily to move materials.
Each year in the United States, nearly 100 workers are killed and
another 20,000 are seriously injured in forklift-related incidents [BLS
1997, 1998].
Forklift overturns are the leading cause of
fatalities involving forklifts; they represent about 25% of all
forklift-related deaths

Fatality Data

The
following paragraphs summarize information about fatalities involving
forklifts. The information is from databases that identify work-related
fatalities in the United States.

National Traumatic Occupational Fatalities (NTOF) Surveillance System

In
the United States, 1,021 workers died from traumatic injuries suffered
in forklift-related incidents from 1980 to 1994. The NTOF Surveillance
System uses death certificates to identify work-related deaths. These
fatalities resulted from the following types of incidents:

Type of Incident

% total victims

Forklift overturns

22

Worker on foot struck by forklift

20

Victim crushed by forklift

16

Fall from forklift

9

Census of Fatal Occupational Injuries (CFOI)

Current Standards

Occupational Safety and Health Administration (OSHA)

OSHA
has developed standards for powered industrial trucks (such as low- and
high-lift trucks and forklift trucks) [29 CFR* 1910.178] and for
forklifts used in the construction industry [29 CFR 1926.600; 1926.602].
*Code of Federal Regulations. See CFR in references.

Training

OSHA
has promulgated the Final Rule for Powered Industrial Truck Operator
Training [29 CFR 1910.178(l)], which became effective March 1, 1999. The
standard requires operator training and licensing as well as periodic
evaluations of operator performance. The standard also addresses
specific training requirements for truck operation, loading, seat belts,
overhead protective structures, alarms, and maintenance of industrial
trucks. Refresher training is required if the operator is observed
operating the truck in an unsafe manner, is involved in an accident or
near miss, or is assigned a different type of truck.

Forklift Maintenance

OSHA
requires that industrial trucks be examined before being placed in
service. They shall not be placed in service if the examination shows
any condition adversely affecting the safety of the vehicle. Such
examination shall be made at least daily. When industrial trucks are
used around the clock, they shall be examined after each shift. When
defects are found, they shall be immediately reported and corrected [29
CFR 1910.178(q)(7)].

Forklift Operation

OSHA requirements for forklift operation are as follows:

On
all grades, the load and load engaging means shall be tilted back, if
applicable, and raised only as far as needed to clear the road surface.
The forks shall not be raised or lowered while the forklift is moving
[29 CFR 1910.178 (n)(7)(iii)].

Under all travel conditions, the
truck shall be operated at a speed that will permit it to be brought
safely to a stop [29 CFR 1910.178 (n)(8)].

The operator shall
slow down and sound the horn at cross aisles and other locations where
vision is obstructed [29 CFR 1910.178 (n)(4)].

The operator is required to look toward and keep a clear view of the travel path [29 CFR 1910.178(n)(6)].

Unauthorized
personnel shall not be permitted to ride on powered industrial trucks. A
safe place to ride shall be provided where the riding of trucks is
authorized [29 CFR 1910.178 (m)(3)].

Forklift trucks shall not be driven up to anyone standing in front of a bench or other fixed object [29 1910.178 (m)(1)].

Fair Labor Standards Act (FLSA) and Youth Employment

The FLSA [29 USC
201 et seq.] (the primary law governing the employment of youth under
age 18) includes work declared hazardous for youth by the Secretary of
Labor. Hazardous Order No. 7, Power-Driven Hoisting Apparatus Occupations,
prohibits workers under age 18 from using forklifts and similar
equipment in nonagricultural industries [29 CFR 570.58]. In agricultural
industries, minors under age 16 are prohibited from using forklifts [29
CFR 570.71 (a)(3)(ii)].United States Code.
Not
all working minors are covered by the FLSA. The regulations in
agriculture do not apply to minors working on their parents' farms. Also
exempted are youths aged 14 and 15 who are working under carefully
regulated conditions in a bona fide vocational agriculture program.

American Society of Mechanical Engineers (ASME)/American National Standards Institute (ANSI)

When work is being
performed from an elevated platform, a restraining means such as rails,
chains, etc., shall be in place, or a body belt with lanyard or
deceleration device shall be worn by the person(s) on the platform
(ASME/ANSI B56.1, §4.17.1[b]) [ASME 1993].

Operation

An
operator should avoid turning, if possible, and should use extreme
caution on grades, ramps, or inclines. Normally the operator should
travel straight up and down (ASME/ANSI B56.1, §5.3.8[d]) [ASME 1993].

The
operator of a sit-down type forklift should stay with the truck if
lateral or longitudinal tip over occurs. The operator should hold on
firmly and lean away from the point of impact (ASME/ANSI B56.1,
§5.3.18[d]) [ASME 1993].

In addition to the above
regulations, employers and workers should follow operator's manuals,
which are supplied by all equipment manufacturers and describe the safe
operation and maintenance of forklifts.

Notice to the Reader

The first edition of this Alert applied only to forklifts operated
in a sitting position. However, this new edition includes a
recommendation for employers and operators of stand-up forklifts with
rear-entry access (see tear-out sheet and pages 6 and 7). In addition,
the revised Alert contains several minor changes in wording to improve
clarity.

WARNING!
Workers who operate or work near forklifts may be struck or crushed by the machine or the load being handled.
Workers: If you operate or work near forklifts, take these
steps to protect yourself.

Do not operate a forklift unless you have been trained and licensed

Use seatbelts if they are available

Report to your supervisor any damage or problems that occur to a forklift during your shift

Do not jump from an overturning, sit-down type forklift. Stay with
the truck, holding on firmly and leaning in the opposite direction of
the overturn

Exit from a stand-up type forklift with rear-entry access by stepping backward if a lateral tip over occurs

Use extreme caution on grades or ramps

On grades, tilt the load back and raise it only as far as needed to clear the road surface

Do not raise or lower the forks while the forklift is moving

Do not handle loads that are heavier than the weight capacity of the forklift

Operate the forklift at a speed that will permit it to be stopped safely

Slow down and sound the horn at cross aisles and other locations where vision is obstructed

Look toward the travel path and keep a clear view of it

Do not allow passengers to ride on forklift trucks unless a seat is provided

When dismounting from a forklift, set the parking brake, lower the forks or lifting carriage, and neutralize the controls

Do not drive up to anyone standing in front of a bench or other fixed object

Do not use a forklift to elevate workers who are standing on the forks

Elevate a worker on a platform only when the vehicle is directly below the work area

Whenever a truck is used to elevate personnel, secure the elevating platform to the lifting carriage or forks of the forklift

Use a restraining means such as rails, chains, or a
body belt with a lanyard or deceleration device for the worker(s) on the
platform

Do not drive to another location
with the work platform elevated

Typical sit-down type forklift
The National Institute for Occupational Safety and Health (NIOSH)
requests assistance in preventing injuries and deaths of workers
who operate or work near forklifts. Most fatalities occur when a
worker is crushed by a forklift that has overturned or fallen from
a loading dock.
NIOSH investigations of forklift-related deaths indicate
that
many workers and employers (1) may not be aware of the
risks of
operating or working near forklifts and (2) are not
following the
procedures set forth in the Occupational Safety and Health
Administration (OSHA) standards, consensus standards, or equipment
manufacturer's guidelines.
This Alert describes seven incidents resulting in the
deaths
of seven workers who were either operating or working near
forklifts. In each incident, the deaths could have been prevented by
using proper safety procedures and equipment and by following the
provisions of the OSHA standards.
NIOSH requests that editors of trade journals, safety and
health
officials, industry associations, unions, and employers in
all industries bring the recommendations in this Alert to the attention
of all workers who are at risk.

Friday, August 8, 2014

Safety and Health Information Bulletin

SHIB 03-09-30

This Safety and Health Information Bulletin is not a
standard or regulation, and it creates no new legal obligations. The
Bulletin is advisory in nature, informational in content, and is
intended to assist employers in providing a safe and healthful
workplace. Pursuant to the Occupational Safety and Health Act,
employers must comply with hazard-specific safety and health standards
and regulations promulgated by OSHA or by a state with an OSHA-approved
state plan. In addition, pursuant to Section 5(a)(1), the General Duty
Clause of the Act, employers must provide their employees with a
workplace free from recognized hazards likely to cause death or serious
physical harm.

Purpose

The purpose of this Safety and Health Information Bulletin is:

To inform employers that youth employment regulations (29 CFR 570)
promulgated under the Fair Labor Standards Act prohibit most employees
under the age of 18 years from operating forklifts for non-agricultural
operations;1

To remind employers that all forklift operators who are 18 years
old or older must be trained and certified as competent to operate
forklifts; and

To identify additional resources for employers to ensure a safe and healthful workplace for all workers.

Background

The Directorate of Science, Technology and Medicine was informed by
the Atlanta OSHA Regional Office, the Boston OSHA Regional Office, and
the Wage Hour Division (WHD) of the Employment Standards Administration
(ESA) of two recent, fatal forklift accidents involving underage
operators that occurred in warehouses in Georgia and Massachusetts. Both
accidents involved operators under 18 years of age. Given the
significant number of young workers employed, especially during the
summer months, OSHA and WHD believe that it is important to remind all
employers of the regulations that prohibit workers under 18 years of age
from operating specified hazardous machines and equipment, including
forklift trucks in non-agricultural operations.

Accident Descriptions

Massachusetts Accident
The forklift operator was a 16-year-old male hired as a summer helper to label bins and move stock by hand around the warehouse.
The warehouse has a forklift, and it was common practice to leave the
forklift's operating key in the ignition switch when the forklift was
not being operated. Prior to the accident, the victim was observed
operating the forklift several times, most recently on the morning of
the accident. He was advised several times by a number of employees not
to operate the forklift.
The victim was not trained nor was he certified as competent to operate the forklift.
There were no witnesses to the accident. However, it is believed that
the victim boarded the forklift, without putting on the seatbelt,
raised the forks with an empty pallet to a height of approximately 10
feet, and drove down the left side of the loading dock ramp. The ramp
slopes away from the building at an angle of approximately 33 degrees on
the left side near the street level (Figure 1).

Figure 1 - Demonstrates a slope of approximately 33 degrees from the wall of building

There was a stack of empty pallets across the bottom of the ramp, and
it appears that the victim was attempting to place the empty pallet on
top of the stack before the close of business. With the forks raised to a
height of approximately 10 feet on a 33 degree slope, the forklift's
center of gravity may have shifted, creating an unstable condition and
causing the forklift to topple sideways (Figure 2). Refer to 29 CFR 1910.178 Appendix A, for further discussion concerning stability of powered industrial trucks. The victim was crushed under the truck.

Figure 2 - Forklift toppled sideways

Georgia Accident
A foreman's 15 year-old step-son was killed while the youth was operating a forklift at the warehouse.
The victim was being shown how to operate the forklift and was
practicing picking up and moving empty pallets. He had just unloaded a
pallet in the warehouse and had picked the empty pallet off the floor
when he lost control of the forklift. The police investigator stated
that the forklift "suddenly went backward, crashing open a closed
loading bay door and drop[ping] four feet to the ground. The victim fell
off [the forklift,] and the forklift landed on top of him." The victim
was pinned to the ground and sustained massive chest injuries.

The Fair Labor Standards Act

Regulations promulgated pursuant to the Fair Labor Standards Act prohibit individuals younger than 18 years of age from engaging in specified hazardous occupational activities. 29 CFR 570.58 - Occupations involved in the operation of power-driven hoisting apparatus
(Order 7), paragraph (a) (5), specifically prohibits employees under 18
years of age from operating forklifts in non-agricultural employment.
Additional orders promulgated pursuant to the Fair Labor Standards
Act prohibit operation of other machines that are hazardous to workers
under 18 years of age. These orders include:

Order 2, driving a motor vehicle and being an outside helper on a motor vehicle;

Other Information

In May 2002, the Secretary of the Department of Labor, Elaine Chao, launched the YouthRules! Initiative to increase public awareness of Federal and State rules concerning young workers. The YouthRules!
web page is a gateway providing quick access to information about
Federal and State labor laws that apply to young workers. The web page
includes information designed to educate teens, parents, educators, and
employers concerning the hours youth can work, the jobs youth can do,
and how to prevent workplace illnesses and injuries. The web page
contains a link to the Fair Labor Standards Act Advisor on "Prohibited Occupations for Non-Agricultural Employees"
which includes the prohibited occupations for 14- and 15-year-old youth
workers, as well as a list of hazardous occupations, which are
prohibited for workers under 18 years of age. Another link of the
Advisor, "Prohibited Occupations for Agricultural Employees"
includes the prohibited agricultural occupations for youth younger than
12, 12- or 13-year-old workers, and 14- or 15- year-old workers.
OSHA also has a webpage for young workers,
http://www.osha.gov/SLTC/teenworkers/index.html, which contains
occupational safety and health information relevant to young workers.
In 2002, the Wage and Hour Division of the Employment Standards
Administration initiated a "STOP" sticker program. As part of that
program, WHD developed a sticker that can be applied to forklifts to
provide a warning regarding the prohibition against workers under 18
years of age operating a forklift. http://youthrules.dol.gov/posters.htm

Conclusions

Employers have the responsibility to comply with 29 CFR 1910.178
in order to ensure the safe operation of powered industrial trucks at
their facility. In addition, since Order 7 of Hazardous Occupations
prohibits employees under 18 years of age from operating forklifts,
employers must make certain that workers under 18 years of age are not
permitted to operate forklifts under any circumstances. Employers who
employ individuals younger than 18 years of age also must be cognizant
of other employment activities prohibited for young workers under the
Fair Labor Standards Act. Employers, educators, parents, and young
workers all are encouraged to visit the DOL and OSHA web pages for
additional information on creating and maintaining compliant, safe and
healthful work environments.

Wednesday, July 30, 2014

Figure 13. Longitudinal stability is lost when the
center of gravity moves too far forward.

Maintaining stability of a powered industrial truck is
easier once you understand a few basic principles. There are many aspects of a vehicle's stability:

The Stability Triangle

Longitudinal Stability

Lateral Stability

Dynamic Stability

NOTE: This discussion focuses on sit-down counterbalanced forklifts.
"Counterbalanced" means that the truck is weighted in the back with
counterweight so that it will not tipover when the load is placed on the front.
The counterweight is located between or behind the rear wheels and provides a
weight in the back to "counterbalance" the weight of the load in the front. For
a brief summary of other types of forklifts, see
Types and Fundamentals.

The Stability Triangle

Figure
14. When
the vehicle is loaded, the combined center of gravity (CG) shifts toward
line B-C. Theoretically the maximum load will result in
the CG at the line B-C. In actual practice, the combined CG should never
be at line B-C.

Figure 15. The
forklift will not tipover as long as the Combined Center of Gravity of the truck and load system remains within the Stability
Triangle.

Figure 16. If the CG shifts outside the boundaries of the stability triangle, the truck will tipover.

Almost all counterbalanced powered industrial trucks have
a three-point suspension system, that is, the vehicle is supported at three
points. This is true even if the vehicle has four wheels. The truck's steer axle
is attached to the truck by a pivot pin in the axle's center. When this point is
connected to the front wheels with imaginary lines, this three-point support
forms a triangle called the stability triangle (Triangle ABC where Point A is
the pivot point in the rear axle and Points B and C are the front wheels).
(Figure 14) [A-4.1,
29 CFR 1910.178 Appendix A]
So long as the center of gravity remains within this stability triangle, the
truck is stable and will not tip over.

When the forklift is not loaded, the location of the forklift's center
of gravity is the only factor to be considered in determining
its stability. In Figure 14, the center of gravity is between the axle
of the steer wheels at A and the drive wheels at
B-C and it is marked with the arrow as the Vehicle Center of Gravity
(Unloaded).In Figure 15,
the combined center of gravity of the forklift and its maximum load shifts
forward toward the load so that it is now located on the line representing the
front axle, at the very edge of the stability triangle. While the loaded
forklift is still theoretically stable, in practice the combined center of
gravity should never reach this line because sudden stops, starts, and turns
could shift the center of gravity further out and destabilize the forklift.

As seen in Figures 16 and 17, a shift of the center of gravity occurs as the forklift is loaded. The
forklift is more stable when it is properly loaded than when it is unloaded.
However, improper loading, such as loading the forklift beyond its capacity, or
loading an oversize or wide load without adjusting the weight, will cause the
forklift to tipover, either laterally on its side or longitudinally forward.
The direction of the tipover will depend on where the combined center of gravity
shifts outside the stability triangle.

Additional Information:

The Powered Industrial Truck Standard has a non-mandatory Appendix which
more fully describes the forces involved and includes figures and
definitions:[29
CFR 1910.178 Appendix A]

Lateral stability is a truck's resistance to overturning sideways.

Dynamic stability refers to the idea that an unloaded forklift's center of
gravity and a loaded forklift's combined center of gravity can shift outside of
the stability triangle as a result of certain movements, such as sudden stops
and starts, turns, or operating on grades.

Line of action is an imaginary vertical line through an object's center of gravity.

Load center is the horizontal distance from the fork's or other attachment's
vertical face to the line of action through the load's center of gravity.

Moment is the product of the object's weight times the distance from a fixed
point (usually the fulcrum). In the case of a powered industrial truck, the
distance is measured from the point at which the truck will tipover to the
object's line of action. The distance is always measured perpendicular to the
line of action. [29
CFR 1910.178 Appendix A]

Figure
17. The
combined center of gravity of the truck and load system shifts forward outside the stability triangle, as the load's moment is
greater than the vehicle's moment, and the forklift tips forward, pivoting on the front axle or
fulcrum.

Figure
18.
The
forklift teeters and finds its balance point. As the load is added to
the seesaw, the moment is increased on the right side. The
loaded forklift reverses and finds a new balance point at its combined
center of gravity.
View Animation

Maintain stability. Keep the combined center of gravity within the stability triangle.

Do not accelerate rapidly or brake suddenly. Sudden changes in direction may also shift the combined center of gravity
outside the vehicle's stability triangle and destabilize it.

Do not turn rapidly. The combined center of gravity may shift outside the stability triangle and may cause the vehicle to
tipover to the left or right.

Never turn on a grade or ramp. Even a 10 percent grade may shift the combined center of gravity outside the stability
triangle and cause the vehicle to roll over laterally.

Cross an obstacle (railroad tracks, beam, pot hole) at a 45 degree angle, so both wheels do not elevate simultaneously.

Maintain control of your vehicle at all times. Adjust your speed to match the conditions. Be aware and anticipate dangerous
motions and avoid them.

Consider the dynamic forces that result when the vehicle and load are put into
motion.
The weight's transfer and the resultant shift in the center of gravity due to the dynamic forces created when the machine is
moving, braking, cornering, lifting, tilting, and lowering loads, etc., are important stability considerations.
[A-7.1.
29 CFR 1910.178 Appendix A]

When determining whether a load can be safely handled, the operator should exercise extra caution when handling loads that are
close to the truck's stated
capacity.

Keep the center of gravity of the load as near as possible to the center
going horizontally across the forks.

Keep the center of gravity of the load as near to the front wheels as possible.

Shifting Center of
Gravity

Figure 10. The
Center of Gravity (CG) is in the center of a symmetrical load but is off center in an irregular load. In the third example, the
CG is outside the boundaries of the object.

Figure 11. A 4,000 pound
truck is balanced by a 4,000 pound load.

Figure 12. Notice the
center of gravity of the load and truck system shift forward toward the front wheels as the load is engaged.

All objects have a specific center of gravity. Gravity is a force that always
pulls objects toward the earth's core. Center of gravity means the point on an
object at which all of the object’s weight is concentrated and all of the parts
balance each other. For symmetrical loads, the center of gravity is at the
middle of the load in terms of the load’s length, width and height. (Figure 10).
Since the capacity of the forklift is based on the assumption of a cube having
the center of gravity in the middle, the shape and position of the actual load
are key factors when determining whether a load can be carried safely.

When a load is placed on a forklift, the key concept is the combined center of
gravity of the forklift and the load. For example, a typical unloaded forklift
weighing 4000 pounds may have its center of gravity about 10 inches (25.4 cm)
above and two feet (0.6 m) behind the front axle, about half way up the truck
body. The heavy counterweight located toward the rear of the forklift places the
center of gravity toward the rear, which keeps the forklift from tipping
forward. In the meantime, a 4,000 pound load consisting of a cube with even
weight distribution has a CG in its center. When the load is placed on the
forklift, the combined center of gravity of the forklift and the load will move
forward, but the forklift will not tipover so long as the weight of the load is
centered and does not exceed the capacity stated on the data plate. But if the
load is too heavy, or if it is placed at the end of the forks so that the load
center distance is increased, the excessive load moment will cause the forklift
to tip forward. Remember, when the forklift engages a load, the combined center
of gravity of both the load and the truck system shift forward from the center
of gravity of the unloaded forklift. (Figure
11 and 12)

Potential Hazards:

Be aware of tipover or falling loads while:

Operating a forklift, as the center of gravity shifts.

Engaging or depositing a load.

Requirements and Recommended Practices:

Handle loads within the capacity of the truck as stated on the data plate.
[29
CFR 1910.178(o)(2)]

Do not operate a forklift if the back wheels begin to lift off the ground. This is an indication that the forklift is
overloaded. The center of gravity has shifted too far forward over the axle of the front wheels and the forklift may teeter on
the wheels.

Never travel with the load elevated. Elevating the load increases the load
center distance by shifting the center of gravity upward and forward, making the
forklift and the load less stable (Figure 5).

Adjust long or high (including multiple-tiered) loads which may affect capacity.
[29
CFR 1910.178(o)(3)]

Keep the center of gravity of the load as low to the ground and as close to the front wheels as
possible:

Carry the load at the lowest position possible, 4 to 6 inches from the ground.

Tilt the mast back and position the heaviest part of the load against the carriage.

Wednesday, July 2, 2014

Figure 5.
Lifting a 5 lb box directly up has the
effect of lifting 5 lbs.

Figure 6. As the distance increases from the shoulder, the moment, or apparent
weight increases so that a 5 pound box seems to weigh 12 pounds.
View Animation

The way in which weight is distributed changes the amount of weight the lift truck will safely carry. You
can experience this for yourself by doing the following activity:

Lift a 5 pound box. As you extend your arms, the center of the box’s weight
moves a greater distance from your body, so the box feels heavier and you will
tend to fall forward. The same idea of increasing the load center distance
applies to a playground see-saw: the farther you sit from the middle, the more
you increase the load center distance and the more force you put on that end.
The same principle—increasing the load center distance—can cause a forklift to tipover.

When the load center distance increases, it is actually increasing something
called the "Load Moment":

Load Moment is the product of the object's weight multiplied by the object’s
distance from the fulcrum, which is a fixed point that acts as the pivot point.
On a sit-down counterbalanced forklift, the fulcrum or pivot point is the axle
of the front wheels. It is this product, or Load Moment, which determines how
much overturning force is being applied to the forklift.

Load Moment = Weight X Distance

Because the overturning force depends on both the weight of the load and the
load’s distance from the pivot point, a forklift’s capacity is always stated in
terms of both: the load’s weight and its load center distance. For example, if a
forklift’s capacity as stated on its data plate is “3,000 pounds at a 24 inch
load center,” this means that the Load Moment cannot safely exceed 72,000
inch-pounds (24-in. x 3,000 lb = 72,000 inch-pounds.) If the load center
distance for the actual load is greater than the standard 24 inches, the only
way to keep the Load Moment from exceeding 72,000 inch-pounds is to reduce the
load. The easiest way to determine the maximum load when the load center
distance is greater than the distance stated on the data plate is to divide the
maximum Load Moment by the actual load center distance. For example:

If a load is 60
inches long (30-inch load center) then the maximum that this load can weigh
is:

72,000 inch-pounds / 30 in-load center = 2,400 pounds

Figure 7. Improperly
distributed loads may tip the forklift if the maximum load moment is exceeded.

Potential Hazards:

While carrying a load near the maximum allowable capacity, be aware of
the following:

Danger of tipover

Danger of losing load

Danger of being struck by falling load

Requirements and Recommended Practices:

Calculate a maximum allowable load moment to determine whether an unusual load, such as
one that is longer than 48 inches (i.e., the load center distance would be
greater than 24 inches) or that has an offset center of gravity (i.e., uneven
weight distribution) can be
handled safely.

Minimize the load center distance measured from the back of the forks to the center of the load. This allows the
forklift to carry more weight.

As illustrated in Figure 7, a truck that has a 4,500 pound capacity at a 24-inch
load center will tipover if a 60-inch load is positioned lengthwise.
Positioning the load in this way increases the load center distance to 30 inches
and increases the load moment by 27,000 inch-pounds.

If the load center distance is 30 inches, the only way to keep the maximum
allowable load moment within 108,000 inch-pounds is to limit the weight of the
load to 3600 pounds:

30 inches X 3600 pounds = 108,000 inch-pounds

Use extra caution when handling extra heavy loads that may approach the truck's maximum capacity. For example, when handling
a maximum load, the load should be carried at the lowest position possible, the truck should be accelerated slowly and evenly,
and the forks should be tilted forward cautiously. However, there is no one rule for all situations.

Maintain control of the vehicle at all times. The operator is responsible for handling the truck.
Drive slower when carrying a load near the maximum allowable.

Do not exceed the stated capacity of your truck. Know its mechanical limits.

Friday, June 27, 2014

Figure 4. Improperly distributed loads
may tip the forklift if the operator exceeds the stated capacity of the
truck. This forklift can carry 4,000 pounds at a 24 inches
load center, but only 2,666 pounds at a 36 inches load center.

Requirements and Recommended Practices:

Estimate the safe load capacity with oversized loads.

If the stated load center is exceeded, compensate by reducing the weight of
the load.

Consult the forklift manufacturer’s instructions when handling large or unusually configured loads.

Tip: Use field calculations to estimate the reduced
lifting capacity if manufacturer’s instructions are not available. This
calculation method will not produce exact load reduction figures. Use
this method only as a guideline. The forklift manufacturer
is the source of more precise information.

Field Calculation of Safe Load
Capacity

Assume a situation where a forklift truck that has a 5,000 pound capacity at a
24 inch load center needs to handle a load whose center is 28 inches from the
front face of the forks in the horizontal direction. The first thing to
recognize is that the actual load center distance of 28 inches exceeds the
standard load center distance of 24 inches on which the 5000 pound capacity is
based, so the safe load capacity is actually less than 5000 pounds.

To estimate the truck's safe load capacity at a 28-inch load center, take the
rated load center and divide it by the actual load center. Then multiply this
number by the stated capacity to get the new approximate safe load capacity:

24 in/28 in x 5,000 lb = 4,285 lb (approximate safe load capacity)

Using the example in Figure 4, take the stated standard load center of 24 inches
and divide it by the actual load center of 36 inches. Multiply this number by
the stated capacity of 4,000 lb to get the new approximate safe load capacity:

Monday, June 23, 2014

Figure 1. As the center of gravity
for the load moves forward, the lifting capacity for the forklift decreases.

The stated capacity of a
forklift only applies to the load center indicated on the data plate. If the
load is not centered at the specified position, the forklift's capacity will be
reduced. Loads come in all shapes and sizes, not just symmetrical
boxes. The load size, position, and weight distribution critically affect the
forklift's capacity and the stability
of the truck. Consider the following factors before engaging a load:

Figure 2. The same 4500 pounds weight loaded properly (top) will exceed the rated capacity of
4500 pounds if the rectangular box is positioned lengthwise (bottom).

Load weight, weight distribution, size, shape,
and position are key factors affecting the stability of the forklift.
Forklifts are
designed to carry a capacity load at a standard load center, commonly 24
inches.
This means that the forklift’s capacity was determined as if the load
were a
cube whose weight is evenly distributed (i.e., whose center of gravity
is
exactly in the center of the cube) and which is resting on a standard
pallet
having dimensions of 48 inches by 48 inches. With such a load, the
horizontal
distance from the center of the load to the vertical part of the forks
would be
24 inches. Of course, most loads are not perfectly shaped cubes having
their
center of gravity exactly in the middle of the cube. To the extent that
the load
differs from this theoretical load — such as if it is irregularly
shaped, has
unbalanced weight distribution, or is not centered on the forks — the
capacity
may be reduced.

Potential Hazards:

While arranging a load, be aware of the following:

tipover

Loss of steering control (Shifting too much weight forward raises the rear wheels.)

Falling load

Collision

Requirements and Recommended Practices:

Do not exceed the capacity of the forklift that appears on the forklift's
data plate (sometimes called the "nameplate"). If the load is oversized, irregularly shaped, or loaded incorrectly, the
actual load center distance could exceed the stated load center distance,
causing the truck's capacity to be exceeded. (Figure 2).

Always minimize the distance from the front wheels to the load center. Load a large rectangular box widthwise across the
forks of the truck as in Figure 2. Placing a large rectangular load lengthwise causes the load center to shift forward
further away from the front wheels, exceeding the truck's capacity and lifting the rear wheels off the ground.

Figure 3. The heaviest weight should be loaded as close to the masts as possible.

Load as close to the front wheels as possible to minimize the load center distance. Load the heaviest part toward the mast.
(Figure 3)

Position the load in a way that will shorten the load center distance.